really hot here in Southern California garages (especially in L.A. inland valley area's, very hot and dry), with no air-conditioning. I'm always concerned about potential deterioration of model's, materials (paint, glue, etc.,...), as well as electronics (ie. RC gear, etc.,...). I try to store RC gear (especially battery packs, etc.,...) inside house (as much as wife allows).
My garage is humanly un-inhabital during hot daytime weather (may be easily 105 - 110F internally). I can only work either early morning or late afternoon/evening. I have to let garage air-out at least 30 minutes upon opening door before going inside to work. All objects are very warm to-the-touch. Gallons of fuel and paint thinner's become pressurized.
Seems to me epoxy-glass models have exhibited more stability under these hot storage conditions (compared to polyester resin-based lay-up's) in my experience. I have an old un-built Dumas (polyester resin) fiberglass deep vee kit in which the un-joined deck has become extremely warped to the point where it will not line-up with the hull, it's useless. While, at the same time, I have two or three Prather epoxy-glass boats, stored sitting on their stands horizontally, that look very good, no warpage (after 25 years of garage storage).